Nina's final Black Swan dance at the end of the film. Damn.
Nina breaking her mom's fingers to get to her performance. This shows her finally and fully breaking free from her Stage Mom's tight grip.
Pretty much any time Nina takes control of her life away from her mother. Since Nina is 28, there's not a damned thing her mother can do about any of it. Nina's shout of "I'm moving out!" which her mom has no response to basically seals the shift of power in Nina's life.
Nina taking charge in the discussion with Thomas about who will dance as she psychs him out and asserts her strength.
After taking shit from so many different people, Nina's comeback to Beth coming up to her and telling her she's not as good enough for the role as her is very satisfying. Beth's face afterwards is solid gold on film.
Beth: What did you do to earn this role? He always said you were such a frigid little girl. How did you get him to change his mind? Did you suck his cock?
Nina:(deadpan) Not all of us have to.
Anytime she calls out her mom on her smothering nature, which is rather often considering who she is while she's doing ballet (repressed, quiet, friendless, silent), shows she does have some sort of fight deep underneath.